Lifting jack



To all whom t may concern;

Patented Aug. 4, 1925.

UNITED srA TEs PATENT OFFICE.

MALCOLM ID. RIKER, OF DOVER, NEW JERSEY, ASSIGNOR TO McKIERNAN-VTERRY DRILL COMPANY, F DOVER, NEW JERSEY, A. CORPORATION NEW JERSEY. i

LIETING JACK.

Application led March 14,' 1922. Serial No. 543,641.

Be it known that I, MALCOLM D. BIKER,

a citizen of the United States of America,

and a resident o f Dover, county of Morris and State of New Jersey, haveinvented ycertain new and useful Improvements in Lifting Jacks, of which the following is a specification. 1

This invention relates to lifting jacks. One o-f the objects of the invention is to provide a jack that will be simple in construction and light in weight but will be very strong'and rugged.

Another object of the invention is to provide a lightweight jack' having a maximum lifting capacity. f

Another object of the invention is to provide a j ack` of the character described that may be economically manufactured.

Further objects will appear from the following description taken in connection with the drawings which form a part of this application. y

Referring to the drawings: 1 Fig. 1 isa sectional elevation of a liftuing jack constructed in accordance with the invention. f'

Fig. 2 is an elevational view, partly Vin',

section of the jack shown in Fig. 1 taken at right angles to Fig. 1.`

, Fig. 3 is a transverse sectional view taken substantially on line 3-3ofFig.l l.

Fig. 4 is a transverse sectional view taken substantially kon line 4--4'of lFig. 1,A and Fig. 5 is a sectional eleva-tion taken subv .stantially on line 5-5 of Figs. 1 and 2.

The ack illustra-ted in the'drawings and constructed in accordance with my invention may be briefly described as comprising a -pair of members formed from commer-cial cylindrical tubing, relatively slidable but relatively non-rotatable with reference to each other.

One of these members is provided with depressed or flat portions and the other member has secured thereto or formed thereon inserts or lugs adapted to engage the flattened portions of the rst member to prevent the relative rotation of the members.

One of these members is secured to a base trated, I have shown a jack having a base of cast or forged metal. A tubular mem- Y ber orpedestal 11 is secured to the base as by weldingshown at 12and the member 11 is formed from commercial cylindrical tub-y ing and two of its sidesas indicated at 13 are vdepressed or flattened throughout their length.` A casing 14 surrounds the pedestal, this casing being also-formed of commercial cylindrical tubing and has a portion of its lower wall cut away. vA lifting toe 16 is formed with upwardly extending portions 16 and with lugs or flattened portions 17 adapted to fit in the cut away portion 15 of the casing 14. Ther lugs 17, extensions 16 and intermediate portion of the toe are welded to the casing as indicated at 15. It will be noted that the.flat1surfaces of the lugs 17 are disposed adjacent the fiat sides 13 of the pedestal 11, securing theV casing 14 against rotation.

Theliftingmechanism comprises a screw and nut and suitable operating mechanism for these parts are hereinafter set forth.,

The nut is shown at 18 and has formed thereon or secured thereto a sleeve portion V19 adapted to fit into 'the upper end of the pedestal 11 and having fla-t sidesv 20 engagable with the 'inner walls ofv` the flat portions 13 to prevent rotation of the nut. The

nut also has a laterally extending-flange 21 the casing. The screw 28 is threaded into the nut 18 and has secured thereto or formed integral therewith a worm gear 29 and an upwardly extending reduced end 30 which 'seats-in an openingv 31 formed in the head v25.y The upper end ofthe portion 30 is recessed-as shown at 32, the recessed portion being .connected by an oil conduit 33 to the outer surface ofthe screw at the point of contact between the screw and the nut.

A roller thrust bearing 34 takes up the thrust between the head 25 and the worm gear 29 and screw 28. A cone collar 35 is seated on the flange 24 of the casing head 22 and is adapted to engage the lower face of the worm gear 29 when the jack is in its lowermost position, the collar thus forming a stop for limiting the downward movement of the jack and also retaining lubricant in the casing head.

The jack is limited in its upward movement by engagement of the portion 17 of the collar 16 with the flange 21 of the nut 18.

An operating shaft 36 is rotatably mounted in a portion. of the head casing 22 and has keyed thereon as shown at 37 a worm 88 which meshes with the worm gear 29. The shaft 36 may be rotated in any suitable manner as by a crank.

The jack above described operates in the following manner. Upon the rotation of the shaft 36 the worm gear 29 is rotated thereby rotating the screw 28. Since the screw 28 is threaded into the nut 18 and the latter is prevented from rotation in the pedestal 11 the rotation of the screw will cause the screw and the lifting head 25 of the casing 14 to travel longitudinally with respect to the pedestal 11. During this relative longitudinal movement the lugs or inserts 17 will prevent any relative rotational movement between the outer casing 14 and the pedestal 11. When the lifting head and casing reach their upper limit of movement the portions 17 will engage the under surface of the flange 21 on the nut 18 thereby preventing further upward movement. Vhen the jack is again lowered to position shown in Fig. 1, the cone collar will form a stop and limit the downward movement.

From the above specification, it will be seen that I have provided a jack that is sim le and ractical in construction has P 1 few parts and is light in weight. Furthermore it will be noted that the jack is extremely rugged in construction and has a large lifting capacity. Moreover, by utilizing commercial tubing the manufacturing cost has been materially decreased.

Although one specific embodiment of the invention has been illustrated and described, it will be understood that the invention is capable of modification and that changes in the construction and in the arrangement of the various cooperating parts may be made without departing from the spirit or scope of the invention as expressed in the following claims.

What I claim is 1. A lifting jack comprising a pedestal having' fiat longitudinal surfaces, a casing surrounding the pedestal, and a, lift-ing toe secured to the casing and having lugs provided with flat surfaces abutting the flat surfaces of the pedestal.

2. A lifting jack comprisinga pedestal of commercial cylindrical tubing having longitudinal indented portions, a casing formed of commercial cylindrical tubing, a lifting toe secured to the casing and having lugs abutting the indented portions of the pedestal.

3. A lifting jack comprising two members, relatively slidable and held againstrelative rotation, a n ut having a flange resting on one of said members, a screw carried by the other member and engaging said nut, and a lifting toe having a lug secured to one of said members, said lug having a flat upper surface engageable with the under surface of the nut flange for positively limiting the relative sliding movement of one of said members on the other members.

4f. A lifting jack comprising a pedestal having a fiat longitudinal surface, a nut having a flange provide with a at under surface resting on said pedestal, a casing surrounding the pedestal, a lifting toe having a lug secured to the casing and engaging the flat surface of the pedestal, said lug having a flatupper surface adapted to engage the under surface of the nut flange to limit the longitudinal movement of the casing on the pedestal,

In witness whereof, I have hereunto set 05 my hand this 27th day of February, 1922.

MALCOLM D. BIKER. 

